Microsoft: Windows 10 will not be sold as a subscription

Microsoft announced that Windows 10 will be a free upgrade for Windows 7 and Windows 8 users during its first year of availability. There was some confusion, however, when Microsoft's Terry Myerson started talking about Windows 10 but did that mean that after the first year it will cost an annually payment or something like that after asking the question Terry confirmed that there will be no additional fees attached to Windows 10, whenever you buy it.

Myerson clarified that Windows 10 users will still get free updates and support for the lifetime of the OS, exactly like past versions of Windows.

There's no subscription model for updates or support or continuing to use the OS. Myerson's reference to Windows simply meant that Microsoft plans to update the OS with smaller, more regular updates rather than the big, chunky updates of past Service Packs.
A year after Windows 10 is first available, it will no longer be a free upgrade for Windows 7 and 8 users. Microsoft will then sell Windows 10 the same way it has sold past versions of Windows.

For the Update: It seems there's still confusion. It is very clear from this post that for the first year it's available, you can upgrade to Windows 10 for free if you have Windows 7 or 8. You will not pay for it. After that year is up, nothing will happen to your Windows 10 license. If you do not upgrade within that year, however, you will have to pay for an upgrade. The offer expires after a year, not the upgrade.